Muzzle-loaded mortar



June 15 ,-1926.

G. S. MAXWELL MUZZLE LOADED MORTAR Filed May 12, 1925 a W WEE WM A I 6mm,

, Patented June 15, 1926.

UNITED STATES GEORGE .5. MAXWELL, OF WASHINGTON, DISTBIGI OF COLUMBIA.

MUZZLE-LOADED MORTAR.

Application and m 1a, 1925. semi no, aaeeo.

v My invention relates to improvements in 1;, muzzle-loading mortars of the artillery type,

,gnd hasfor its object extreme rapidity of I can be secured with the existing -types muzzle loading mortars.

To the accomplishment of the foregoing and such other objects as may hereinafter appear, the invention consists in the method and in Ctihe means hereinafter particularly describe Land then sou ht to be clearly defined by the claims, reference being had to the accompanying drawings forming a part hereof, and in,which Figure 1 is 'ian assembly view of a side elevation of tlie mortar partly in section,

' showing one manner of mounting, and the Figure 2 is a sidev elevation of the projectile partly in section, used with the mortar and illustrates the method of securing rotation by means of an expansible rifle band, and also the propellant charge and its pil'imer mounted on the base of the projecti e;

Figure 3 is an enlarged view of the expansible rifle band, partly in section; also of the, mortar, and projectile, with parts broken away;

Fi I re 4 is a view of an alternate or modified orm of rifle band, partly in section.

I am aware that muzzle loaded mortars or guns with rifled barrels and using proectiles with expansible rifle bands have eretofore been used, these mortars or guns however, used a separately loaded propel lant' and primer which were firedby means external to the barrel. The pro ectile was also seated in place by means of a' ramrod instead of bein seated and fired by means of its own weig t as in my invention.

I am also aware that smooth bore mortars using projectiles supporting the propellant charge and its primer have been constructed and that the propellant charge and its primer, carried by the projectile, were fil rl'ed by means of the weight of the projec- This type of mortar is, however, limited 5 in its range, owing to lack of stability and the tumbllng of its rojectile. The greatest range of the 4" S tokes mortar, which .is typical of this type of smooth bore m rtar is 1030 yards, while a mortar emb'o' ying my invention, and using the same powder greater accuracy and longer ranges than.

charge as the 4 Stokes mortar. gives an increase in range over the smooth bore of over 163 per cent with greatly increased accuracy of fire at all ranges.

I am not aware, however, that a muzzle loaded mortar provided with a rifled barrel In the operation of my invention the barrel of the mortar is supported in any suitable manner, on a base plate, spade or other mounting that allows the barrel to be placed. at such an angle with the horizontal that a projectile inserted into its muzzle will fall or slide from the muzzle to the breech of the barrel by means of its own weight.

A projectile having an expansible rifle band attached to the rear end of its body and carrying a propellant charge and its primer supported on a primer firing pin attached to the base of the projectile, is inserted into the muzzle of the mortar and allowed to slide by its own weight to the breech of the barrel, At the instant the projectile reaches the limit of its downward travel in the bar rel thefiring pin on the base of the projectile strikes against the primer and compressing it a ainst the-breech of the mortar causes it to detonate and ignite the propellant charged i The ignition and explosion of the propelland charge instantly produces a high ipressure in the propellant chamber of the mortar and this pressure aotin against the expansible portion of the ri e band forces it into the grooves of the rifling and continuing its pressure against the rifle band forces it. and the projectile, to which it is attached, forward, at the same time that rotation is transmitted from the expanded rotating rifle band to the body of the projectile to rotate and thus stabilize it, during its flight.

In my invention, great rapidity of accurate firing at any range within the capacity of the mortar is obtained. The only limit to rapidity of fire being the time required for the projectile to slide into the barrelfrom the muzzle to the breech, plus the fraction of a second necessary for the exploded propellant charge gases to drive the projectile from the muzzle of the mortar. In actual firings as many as thirty rounds per minute have been secured when using projectiles weighing 25 pounds each.

The most-important feature of my invention, however, is the novel combination of a rifled barrel and rotating means attached to the projectile with a fixed propellant charge and its primer niountedon the base of the projectile and adapted to be fired by means of the weight of the projectile.

Referring to the accompanying draw- 1n Tn Figure l, A is the barrel of the mortar, B the internal rifling in the barrel, C 1s a base plate provided with a receptacle 0. for the rounded breech, b, of the barrel. 1) is a collar clamped to the barrel that pivot-ally engages the biped E atd, and 1 is a pin or stud inside the breech 1) against which the primer of the propellant container may strike when the of the barrel.

Means for elevating or traversing the barrel are not shown, as they do not constitute part of my invention;

In Figure 2,. the projectile body G is proprojectile reaches the breech vided at either end with an annular bearing surface H that is of greater diameter than the projectile G for the purpose of reducing friction between the interior of the barrel -A and the projectile.

K is an expansible rifle band provided with an annular groove X, the arched side of which faces the propellant chamber S. The expansible rifle ring K is secured to the projectile by means of a shoulder e on the body L of the firing pin 0 and the screw M which is integral with the body L of the firing pin 0. v

A propellant container R and a centrally located cup Q integral therewith, constructed of nitrotite, celluloid or other semi-flexible inflammable material are fitted to the projectile by means of friction between the outer wall of the propellant container R and the inner surface of the expansible rifle band K, and also by friction between the interior wall of the cup Q and the reduced portion N of the body L of the firing pin-O.

The space S of the propellant container R is filled with any suitable propellant charge.

A primer P capable of detonation by. means to the projectile.

of friction or compression, is cemented in place at the bottom of the cup Q and immediately below, the point of the firing pin 0 where the propellant container is assembled A percussion fuse W is provided at the forward end of the projectile in the usual manner.

In Figure 3, A is a portion of the barrel showing the rifling B. Mounted in the barrel A the rear endof a projectile G, H, is

shown with its attached rifle band K ex-- panded into the rifiing B as the result of pressure exerted by the explosion of the propellant charge.

in Figure l, a driving disc T provided with a tapered edge f is mounted in the interior of the rifle band K. This disc T is adapted to be driven forward into the tapered side of the rifle band K and by wedging action Will force the rifle band It into the rifling B of the barrel A. The disc will be driven forward by the force of the explosion of the propellant in the container. The container B may be practically the same as the container described for the first form described and attached or held in place by friction between the inner wall of the cup Q, and the reduced portion of firing pin U.

The operation is obvious from the foregoing description; and the advantages over muzzle loaded mortars with rifled barrels in which the projectile is seated by handmanipulated means and fired by means ex ternal to the barrel, and. also over smooth bored mortars in which the projectile is fired by means of the weight of the projectile upon reaching its seat by gravitation, are apparent to the skilled in the art in the light of the description given. The embodiment of the two different types or ideas in a single mortar results in attaining greater rapidity of fire, greater accuracy and longer ranges than is possible in a mortar of either one'of the two distinct types, due to the modifying infiuences ,of .one upon the other when employed in conjunction with each other as has been demonstrated in actual practice.

I have illustrated and described with particularity the preferred details of the several parts of my invention, but changes can be'made without departing from some of the material features and it will also .be understood that the form of embodiment of my invention may be changed and essential features of the invention retained.

Having described my invention and set forth its merits, what I claim is 1. In a muzzle loaded mortar, a projectile for the mortar provided with an expansible rifle band, a rifled barrel for gravity feed of the projectile to its seat and engagement of the expansible rifle band with the rifling, a propellant chargemounted on the base ofthe projectile, a primer for igniting expelling the projectile and concurrently expanding the expansible rifle band, and means in the barrel for engaging the expansible rifle band and rotating the projectile.

3. In a muzzle loading mortar, a propellant charge carried by the projectile and ignitable by impact wlth the breech of the mortar for ejecting a projectile, a primer for igniting the propellant charge, means for igniting the primer, a rifled barrel for receiving the projectile and feeding it by' avity to its seat, and a projectile provided'with an 'expansible rifle band for ture.

GEORGE S. MAXWELL V 

